Elastic-fluid turbine.



PATENTED MAY 19, 1908.

Ml MATTHEWS.

1 ELASTIC FLUID TURBINE. APPLICATION FILED MAE. 25, 1907. RENEWED APR. 14. 190B.

3 SHEETSSHEET 1.

INVENTOA.

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WITNESSES:

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No. 888,248. v PATENTED MAY 19, l908 M. MATTHEWS.

ELASTIC FLUID TURBINE.

APPLICATION TILED MAR. 25, 1907. RENEWED APR. 14, 12108.

3 SHBBTBSHBBT 2.

WITNESSES: INVENTOR.

No. 888,248. PATENTED MAY 19, 1908.

M MATTHEWS ELASTIC FLUID TURBINE.

APPLIOATION FILED MAR. 25. 1907. RENEWED APR. 14. 190B.

3 SHEETSSHEET 3.

INVENTOR.

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A TTO E y.

WITNESSES:

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MARMADUKE MATTHEWS, OF BRACONDALE, ONTARIO, CANADA.

ELASTIC-FLUID TURBINE.

Specification of Letters Patent.

Application filed March 25, 1907, Serial No. 364,526.

Patented May 19, 1908. Renewed April 14, 1908. Serial No. 427,007.

To all whom it may concern:

Be it known that I, MARMADUKE MAT- THEWS, of the village of Bracondale, in the Province of Ontario, Canada, have invented certain new and useful Improvements in Elastic-Fluid Turbines, of which the following is a specification.

My invention relates to turbines of the parallel-flow type in which nozzles are employed to direct the elastic fluid into the buckets of a rotatable bucket wheel, and my object is to design a turbine of that type in which the buckets and guide blades may be cut by any ordinary milling machine, in which the area of the stationary guide blades relative to the movable blades or buckets is reduced to a minimum, in which loss due to the rebounding of steam against the backs of the buckets is entirely avoided, and in which the number of nozzles in use may be readily controlled to control the expenditure of the fluid employed.

Figure 1 is a longitudinal section of my improved turbine. Fig. 2 is an end elevation, partly in section, of the same. Fig. 3 is an enlarged side view of part of one of the first bucket wheels. Fig.4 is a section through the same with part of a ring of stationary vanes behind it on the line ."c i Fig. 3. Fig. 5 is a plan view of a modification of the first bucket wheel. Fig. 6 is a side view of the parts shown in Fig. 5. Fig. 7 is a sectional detail of the same on the line a; y, Fig. 6. Fig. 8 is a similar view taken from the other side of Fig. 5. Fig. 9 is a side elevation showing a modification of the stationary vanes. Fig. 10 is a longitudinal section showing fans connected to the shaft to aid the escape of dead steam from the operative parts. Fig. 11 is an end view of the turbine showing a fan in dotted lines.

In the drawings like letters of reference indicate corresponding parts in the different figures.

Referring particularly to Figs. 1 and 2, A is the casing of the machine, of any suitable construction. In this casing is journaled the shaft B. For the purpose of conferring flexibility on the shaft to compensate for any slight want of balance I prefer to employ a flexible shaft support, which may be of any well known type ordinarily employed. I illustrate for this purpose ball and socket bearings C.

Formed in the casing is an annular steam duct D. In the drawings the engine is shown as double, with the steam flowing towards each end from the center consequently two steam ducts D are shown separated by a diaphragm E.

The bottom of each chamber is formed by a ring F, in which are formed a plurality of nozzles G, preferably of the expanding type shown. These nozzles guide the steam to the :lirst bucket wheels H, the buckets of which are formed as hereinafter described. A large number of the nozzles G, it will be seen, are employed, and for the purpose of adapting the quantity of steam employed to the work being done it is necessary to provide means whereby a larger or smaller number of these nozzles may be employed, as desired. I therefore provide in each duct one or more gates I, which are movable across the ducts to close off a portion of the same. In the drawings I show three of these gates. Of course more or less may be used as desired.

The steam enters each duct through themlet port J; consequently by closing the gate remote from the inlet one quarter of the duct may be cut oil and the nozzles communicating with that portion thus become inoperative. By closing the other gates in succession one half or three quarters of the duct may be cut off from co nnunication. with the steam inlet. This gives me very effective control of the power of the engine much more conveniently than by controlling individual nozzles in the manner previously employed.

The gates may be moved in any desired manner. I prefer, however, to make them slidable in the guides K by means of thescrews L, which are threaded into the gates and extend out through the casing.

A collar M on each screw bearing against the casin g provides a thrust bearing for the screw within the casing. A stuffing box N is also provided for the stem of each screw whereby the apertures for the screws in the casing may be made steam tight.

A hand wheel 0 is provided for each screw whereby it may be operated. The hub of each hand wheel engages the stufling box to prevent the screw from moving inwardly when the gates are being moved to open up the steam ducts.

In steam turbines of the single impact type there is generally considerable loss owing to the steam after impact with the working face of a bucket rebounding against the front of the next bucket behind, or having its energy dissipated in other ways without doing useful work. I aim to overcome this difficulty in my engine by so shaping the buckets of the first bucket wheel with which the steam contacts that the steam strikes the bucket at a comparatively small angle, the

first discharge laterally from said bucket being in an aXial direction, but at such an angle that it may be caught by a series of stationary vanes and re-directed into the second bucket wheel, where more of the energy of the steam is extracted therefrom.

The steam once given what is commonly known as aparallel flow may of course be conducted through any desired number of steps necessary to exhaust the kinetic energy of the steam. The steam, as shown, preferably enters the buckets transverse to the axle, and the buckets themselves are formed by milling notches in the edges of the bucket wheel on chords of arcs of the wheel, so that each bucket in shape is substantially a portion of the segment of a disk intersecting the rim of the wheel.

The shape of each bucket will perhaps be best seen on reference to Figs. 3 and 4 of the drawings.

The bottom P of the bucket, it will be seen, is out so that the steam strikes thereon at a small angle and is reflected of course at the same angle. By dotted lines the course of the central particles of the jet of steam is indicated in Fig. l. When starting the engine the buckets are stationary, and it will be seen that each particle of steam has three impacts on the bucket. l/Vhen the wheel reaches running speed the bottom of the bucket will probably reach the dotted position I before the second impact of a particle of steam oc curs. Hence when running at full speed two impacts alone will probably be obtained. The steam leaving the bucket strikes one of the stationary vanes Q, formed on a ring secured to the casing, and after one impact therewith is directed into the buckets of the second bucket wheel R, and after contact therewith may be exhausted to the atmos phere, or if desired pass through a further se ries of stationary and rotary parts.

As a modification the buckets may be shaped as in Figs. 5 and 6. In this construction the first bucket wheel H is formed in two parts bolted together. In the first part the buckets are milled, as before, on the chords of arcs, but the rim of the disk is about half the width of the rim of the wheel shown in Figs. 1 to l. The remaining width of the wheel is made up by the second disk S, in which are milled substantially radial buckets T inclined rearwardly from the first disk. By rearwardly is meant relative to the direction of rotation of the disk. The cuts formed by the milling tool, and which form the bucket, are so proportioned that the cross sections where they join are of substan tially the same size and configuration, and no kmetic energy l rially to the efficiency of jog appears. These buckets act in substantially the same way as the buckets already described, and will give, under running condi tions, two impacts before the steam reaches the series of stationary vanes.

With my construction many advantages are attained. I find it possible to use the of the steam by impact upon the first bucket wheel at a'small angle thereto thus avoiding re-action by rebounding on the following buckets. As the kinetic energy of the steam, under these conditions, is not entirely abstracted it is redirected by the stationary vanes into the second row of buckets, which kee s up the work begun by the first row of buc iets.

As the buckets are cut on chords of arcs I so set the stationary vanes Q that each one is substantially at right angles to the chord of any bucket with which it may be in alinement, so that the steam is thus properly di rected into the second row of buckets.

In Fig. 9 I show the faces of the stationary vanes curved into filling up the angles seen in Figs. 3 and 4. As no angular corners are found in the bucket wheels the steam in the whole of its course through the turbine after entering the nozzle finds no angular corners to hold dead steam, or create eddies, and this I find adds matethe turbine. It is also of great advantage that I am enabled to cut my buckets from solid disks by means of a milling machine, as this not only makes the construction comparatively cheap but makes the machine also much stronger than those in which the buckets or vanes have to be separately shaped and subsequently secured in place. I consider it also of great advantage that the steam in my device is in contact with moving parts to a much greater extent than with stationary parts as tends to increase the efficiency of the machine owing to the reduction of frictional losses.

I have found in practice that with a 9 wheel rotating at 45,000 revolutions per min ute I obtained 41 horse power at the brake, but I consider that by taking up the kinetic energy of the steam by a series of impacts the turbine may be run economically at a lower rate of speed than single impact engines.

In Figs. 10 and 11 I show a fan Uconnected to the shaft close to the last bucket wheel at each side of the engine. These fans are sufficient to tend to produce a slight vacuum and aid in clearing the working parts of dead steam. I find that efficiency is materially promoted by this means.

What I claim as my invention is z 1. In an elastic fluid turbine the combination of two bucket wheels each provided with a series of similar buckets each shaped to receive and turn the fluid in a plane substantially parallel to the axis of the turbine and intersecting the wheels on the chord of the base of the ring, thus this arrangement an arc; and a plurality of guide vanes intermediate the wheels set to reflect the fluid from the buckets of the first wheel into the buckets of the second.

2. In an elastic fluid turbine a bucket Wheel provided with a series of similar buck ets formed in its periphery, each bucket being formed substantially similar to a part of a segment of a circular disk intersecting the rim of the wheel on the chord of an arc in combination with a wheel secured beside the aforesaid wheel, and having its rim slotted to form approximately radial buckets adapted to receive and deflect rearwardly and axially steam received from the buckets of the first wheel.

3. In an elastic fluid turbine the combination of a bucket wheel provided with a series of similar buckets, each shaped to receive the fluid circumferentially and to discharge it axially, and each shaped to cause a bending of the fluid in a plane substantially parallel to the axis of the turbine by means of a lurality of impacts in the bottom of the hue :et; a second bucket wheel; and an intermediate series of guide vanes adapted to receive the fluid from the first wheel and after a single impact to direct it into the buckets of the second wheel.

4. In an elastic fluid turbine the combination of two bucket Wheels each provided with a series of similar buckets each shaped to receive and turn the fluid in a plane substantially parallel to the axis of the turbine and intersecting its wheel on the chord of an arc; and a plurality of guide vanes at right angles to said planes intermediate the wheels set to reflect the fluid from the buckets of the first wheel into the buckets of the second.

5. In an elastic fluid turbine an annular steam duct; a plurality of nozzles opening therefrom, and a plurality of gates adapted to close the duct at different points in its circumference; and means for operating said gates from outside the turbine.

6. In an elastic fluid turbine the combina tion of a bucket wheel provided with a series of similar buckets formed substantially similar to a part of a segment of a circular disk intersecting the rim of the wheel on the chord of an arc, and shaped to receive the fluid circumferentially and to discharge it axially after a plurality of impacts in the bucket; a second bucket wheel and an intermediate series of guide vanes adapted to receive the fluid. from the first wheel and after a single impact to direct it into the l buckets of the second wheel.

7. In an elastic fluid turbine the combination of a bucket wheel provided with a series of similar buckets each shaped to receive the fluid at one side and to discharge it from the other in an axial direction and each shaped to cause a continuous bending of the fluid backward and axially by means of a plurality of impacts in the bottom of the bucket; and a nozzle adapted to direct the fluid into the bottom of the bucket at a small angle thereto.

8. In an elastic fluid turbine the combination of a bucket wheel provided with a series of similar buckets each shaped to receive the fluid at one side and to discharge it from the other in an axial direction and each shaped to cause a continuous bending of the fluid backward and axially by means of a plurality of impacts in the bottom of the bucket; a nozzle adapted to direct the fluid into the bottom of the bucket at a small angle thereto; a second bucket wheel and an intermediate series of guide vanes adapted to receive the fluid from the first wheel and after a single impact to direct it into the buckets of the second wheel.

9. In an elastic fluid turbine the combination of a bucket wheel provided with a series of similar buckets each formed substantially similar to a part of a segment of a circular disk intersecting the rim of the wheel on the chord of an arc, and shaped to receive the fluid at one side and to discharge it from the I other in an axial direction after a plurality of impacts in the bucket; and a nozzle adapted to direct the fluid into the bottom of the bucket at a small angle thereto.

10. In an elastic fluid turbine a ring of stationary axially directed vanes in which the vane faces are curved into the ring base.

Toronto, Ont., 11th March, 1907.

MARMADUKE MATTHEWS. Signed in the presence of I J. EDW. MAYBEE, 1 JOHN G. Humor. 

